Plant-based diets for healthy aging
Plant-based Diets and Healthy Aging - the Tzu Chi Aging Study (TCAS)
This project will test whether vegetarian and plant-based diets help middle-aged and older Tzu Chi volunteers maintain physical function and cognitive health as they age.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 5000 (estimated) |
| Ages | 40 Years and up |
| Sex | All |
| Sponsor | National Health Research Institutes, Taiwan Academic / other |
| Locations | 1 site (Dalin, Chiayi) |
| Trial ID | NCT07151365 on ClinicalTrials.gov |
What this trial studies
This prospective cohort will recruit about 5,000 Tzu Chi volunteers aged 40 and older and follow them with comprehensive 2-day health examinations at Dalin Tzu Chi Hospital every three years. Diet is measured with a validated food frequency questionnaire, a new Taiwan Diet Quality Calculator (validated in a subcohort), and optional food diaries, while blood biomarkers and genetic data are collected to characterize nutritional status and risk factors. The study links dietary patterns, nutrient biomarkers, physical function tests, sarcopenia measures, and cognitive assessments to examine how plant-based and vegetarian diets relate to aging-related outcomes. Because the cohort has a high proportion of vegetarians and low smoking and alcohol use, researchers expect reduced confounding when interpreting diet–health relationships.
Who should consider this trial
Good fit: Tzu Chi Foundation volunteers aged 40 or older who can attend the 2-day comprehensive health examination at Dalin Tzu Chi Hospital and complete dietary and health questionnaires are ideal candidates.
Not a fit: Individuals with diagnosed dementia or severe cognitive impairment who cannot complete questionnaires, and pregnant people, are excluded and will not be able to participate or gain direct benefit from this protocol.
Why it matters
Potential benefit: If successful, the findings could inform dietary and lifestyle recommendations that reduce risk of sarcopenia, cognitive decline, and other age-related conditions and help older adults preserve function.
How similar studies have performed: Previous Tzu Chi cohorts have reported protective associations between vegetarian diets and lower incidences of diabetes, stroke, gout, cataracts, insomnia, and gallstones, but randomized evidence on causal effects remains limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age 40 years or older. * Volunteers of the Tzu Chi Foundation. * Participating in the 2-day comprehensive health examination program. Exclusion Criteria: * Pregnant individual. * Diagnosed with dementia or poor cognition resulting in inability to answer questionnaires.
Where this trial is running
Dalin, Chiayi
- Dalin Tzu Chi Hospital. — Dalin, Chiayi, Taiwan (Recruiting)
Study contacts
- Principal investigator: Hsueh-Ting Chiu, PhD — National Health Research Institutes, Taiwan
- Study coordinator: Hsueh-Ting Chiu, PhD
- Email: tinachiu@nhri.edu.tw
- Phone: +886-5-6325080
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.